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Calculating NO2 emissions


I'm interested in an indicator that calculates the proportion of NO2 emitted by traffic that is sequestered by urban green. I found some interesting papers that provided tones of NO2 sequestered by ha and year of urban green (mainly urban forests).

Therefore, I need to calculate the emissions of traffic. The NO2 overlay provides annual average concentrations which cannot be used in mentioned indicator. I know I can calculate emissions using next formula from your model:

E = N [(1-FS)((1-(fm+fz+fb))El + fm Em + fz * Ez + fb * Eb) + FS * ((1-(fm + fz + fb)) * El,d + Fm * Em,d + fz * Ez,d+fb*Eb,d)]*1000/(24*3600)

However, I cannot figure it out how to calculate the length of roads since they are polygons. Is there a way to know the width of roads so then I could calculate the length?

Thank you.



  • Hey Joseph,

    At this time it is a bit of a chicken-and-egg type of question. Knowing a length or a width allows you to calculate the other. But because a road can be an arbitrarily-shaped polygon, a length and a width can be any direction of the polygon, assuming it's even a rectangle (or rectangle-ish). Our visualization does make use of a centre line to show moving vehicles, which requires knowing an orientation, but that information is is not directly exposed in the user-space.

    Looking at the context of your question, you seem to indicate that you are looking at a yearly sequestration, but that Tygron's calculation of yearly averages is insufficient for this. Could you clarify why a result of the yearly averages doesn't work for your purposes?

    Kind regards,

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